To better understand the problem solved by the present invention, there is shown in FIG. 1 a known PSA installation according to the state of the art.
The PSA installation shown in FIG. 1 comprises at least two pairs of adsorbers I, II, III, and IV which operate by being offset in time from each other according to a predetermined cycle comprising phases of adsorption, regeneration and pressure increase. Such a cycle generally comprises the steps of balancing pressures between two adsorbers during phases of regeneration and pressure increase.
PSA installations moreover comprise various conduits common to all the adsorbers I, II, III, and IV, namely a supply conduit 1, a production conduit 2, a pressure balancing conduit 3 between two adsorbers, an elution conduit 4, and a conduit 5 for evacuation of the residual gases.
Each adsorber I, II, III, IV is connected at its inlet and at its outlet to a respective associated distributor conduit 6. The terms "inlet" and "outlet" designate the inlet and outlet ends of an adsorber in the adsorption phase.
Individual connecting conduits 7 with valves ensure connection between the distributing conduits 6 associated with the different adsorbers I to IV and the common conduits 1 to 5.
At the level of the distribution conduits 6 and the common conduits 1 to 5, the connections of the connecting conduits 7 are carried out either by means of T connectors 8 whose coaxial fittings are disposed in the distributing conduits 6 or in the common conduits 1 to 5 and whose handles perpendicular to the fittings are welded to the tubes forming the connecting conduits 7 with valves, either by means of elbows 9 when it is a matter of connecting a connecting conduit 7 to one end of a distributing conduit 6 or of a common conduit 1, 2, 3, 4 or 5.
Moreover, each connecting conduit 7 is formed by two sections 10 and 11 of straight tubes, interconnected by an elbow 12, one first section 10 comprising a valve 13 and extending perpendicular to the associated distribution conduit 6 and a second section 11 extending parallel to this conduit 6.
Such an installation has several drawbacks connected to the arrangement of connection of the adsorbers I to IV to the common conduits 1 to 5. Thus, this known arrangement of connections is complicated, such that the valves 13 are not always easy of access to carry out the maintenance operations. Moreover, this arrangement of connections requires a large number of T-shaped connectors and of elbows. Thus, in the installation shown in FIG. 1, there can be counted 24 T connections and 35 elbows.
To assemble the various conduits and valves disposed in the latter, by means of a support frame, such that they form an S structure commonly known as a "valve skid", (indicated in FIG. 1 by broken lines), these numerous T connections and elbows require the provision of a high number of welds, which increases also the cost of production of such an installation.